BARCELONA, Spain - The CEOs of AT&T, Vodafone and Telefonica — three of the world's largest cellphone companies — say U.S. regulators are doing better than their European counterparts in promoting faster wireless data networks.

AT&T CEO Randall Stephenson told an audience at Mobile World Congress, the world's largest cellphone trade show, that the U.S. practice of selling phone companies large swathes of space of the airwaves for perpetual use was helping encourage U.S. companies, including AT&T, to build out large networks using the latest "LTE" technology.

By contrast, many European countries only lease out space on their airwaves for eight- to 15-year terms. The perpetual licenses in the U.S. give phone companies the incentive to invest, Stephenson said.